Improvement in insulators for telegraph-wires



D. BROOKS. .-INsULAToR PoR 'rm-:GRAPH WIRES.

UNITED STATES PATENTOEEICE.

DAVID BROOKS, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN `INSULATORS FOR TELEGRAPH-WIRES.

Specification forming part of LottersPat-ent No. 45,221, dated November29, 1864.

To all 'whom it may' concern:

Be it known that I, DAVID BROOKS, of Philadelphia, Peunsylvaniah'ave invented an Improvement in Insulators for Telegraph-Wires; and I do hereby declare the following to be a full, clear, and exact description of the same, reference beinghad to the accompanying drawings, and to the letters oi reference marked thereon.

My invention consists ot' the improved mode, fully described hereinafter, of constructinginsulators for telegraph-wires, whereby the inconveniences resulting from the collection of Water on and about the insulators during rainy and foggy weather are obviated.

In order to enable others skilled in the art to make and use Iny invention, I will now proceed to describe its construction and operation.

On reference to the accompanying drawings, which form a part of this specitlcation, Figure l is an exterior view of my improvedinsulator for telegraph-wires, and Fig. 2 a vertical section of the insulator inverted.

A is the exterior east-iron casing ot' the insulator, the projection a of which serves as a means of attachment to the arms of the telegraph-poles.

B is a cylindrical block of glass, between which and the interior ot1 the casing A intervenes a body, D, of sulphur, the glass -being considerably shorter than the casin g. In this glass block is a circular opening for the reception ot' the wire-holder G, whichis secured by a mass of sulphur, H, the stem ot' the holder being made concave at opposite sides, so that it cannot be withdrawn from the glass by the weight or tension ot' the wires.

In preparing my improved insulators, I in the rst instance place the glass on a table or slab and pourinto the opening melted sulphur and then deposit the stem of the wire-holder Gin the opening ct' the glass, which is perfeet-ly secured to the holder when the sulphur has become hard by cooling. After this I cement to the upper edge of the glass a strip of paper, h, made in the form of a hollow cylinder, when the glass with its wire-holder is ready for attachment to the casing A. In order to do this I in the first instance heat the casing and then pour into the same a suitable quantity of molten sulphur, and into this I deposit the glass block with its paper cylinder h. As the latter extends to the upper edge of the-easing A there will necessarily be a body of sulphur between the said casing and the paper.l The sulphur and the paper at the upper edge vof the easing A are then trimmed oft', after which, while the insulator is still in an inverted position, moltenparaine is poured into the space above the glass within the paper cylinder until the space'is full. The insulator is then turned upside down, and the greater portion et the molten paraftine poured out, the remainder adhering to the paper and to the upper edge of the casing and sulphur, for care should be taken that the coating1 i of paratne extends over the edge of the casing.

W'hen the coating of paratdne has congealed I cover it with a varnish composed of beeswax, rosin, and parafiine, when the insulator is complete and ready for being attached to the pole in the position seen in Fig.

Although sulphur affords an excellent medium for securing the wireholder to the glass and the latter to the exterior casing oftheinsulator, and although sulphur when dry is a comparatively good non -conductor of electricity, it has a great affinity for water, with which, during rains or fogs, it soon becomes charged to such an extent as to neutralize its nonconducting properties; hence during raiIiIy weather the sulphur would have a tendency to conduct the moisture from the edge of the casing to the wire-holder and through the paper were it not for the coating of paraiine, which penetrates the sulphur, adheres to the surface of the same, and effectually prevents the access of moisture to the wire-holder, the stem of which is also coated with parafne and varnishcd.

I claim as myinvention and desire to secure by Letters Patent- 1. The use in the manner described of a hollenr cylinder, h, of paper or its equivalent, in connecting the glass block B to the casing A by means of sulphur.

2. Coating the interior of the space above the glass block, as well as the edge of the casing and of the sulphur near the same, also the stein of the wire-holder, with parane, in the manner and for the purpose described.

In testimony whereofl I have signed my name to this specification in the presence of two sub scribin g witnesses.

D. BROOKS. Witnesses:

HENRY HowsoN, JOHN WHITE. 

